Compound vacuum pump



jun@ 192%.

C. EISLER COMPOUND VACUUM PUMP Filed June 26, 1925 INVENTOR @n/b@ mwww.. 0 .1/l

ATTORN EY Patented -.l une 5, .1928.

UNIT-ED STA-TES CHARLES EISLEB., or NEWARK, NEW JERSEY.. f

conrounn vacuums rum.

Application tiled v.Tune 26, 1925. Serial No. 89,708.

This invention relates to vacuum pumps. The object of the invention'generally isa high' vacuum pump of.'` novel constructionl and operationwhich is particularly adapted to luse in exhaust machines for exhaustingradio tubes and lamp bulbs. A further ob ject of the invention is` apump construction of this character which is characterized by thesimplicity of'its parts and construction, may be readily assembled ordisassembled with a minimum of attention and labor, and lends itselfgenerally to inexpensiveand economical manufacture. In carrying out myinvention Ihave devised a compoundhigh vacuum pump which is capable of'function.

ing in arpeculiarly satisfactory manner in the exhausting of radio tubesvand lamp bulbs and otherwise possesseslnov'el and advantageous featuresof construction.

For a better understanding of the invention, reference `ma fbe had to`the accom; panying drawings orming a part of this application, wherein:

Fig. `l is a plan view of the pump, Fig. 2 is a sectional view alongtheline 2-2 of Fig. 1, Y f

Fig 3 is a front view of the machine, Fig. 4 isfa view -of the lrotorpiston assembly, w 'a Fig. 5 is a plan view of one rotor and itspiston-blades, I

Fig. 6 is an end view thereof, Figs. v7. and 8are details, and

Fig-9 is a diagrammatic v1 the pump connections.

Referring to the drawings where like numerals designate", lsimilarVparte throughout, I have'indicated my` invention as embodied in acompound pump contained in a housing 9, the latter in the particularembodiment shown being of rectangular shape, and the housing 9 iscarriedby a suitable base 9. -The pump casingcon'sists essentially offive transverse sections, 1, 2, 3` 4, 5 which are assembled together inabutting relation to form cylindrical chambers for the recep-y tion ofthe cylindrical rotors,7,.7, with surrounding eccentric? chambers 18which are traversed by the piston blades 12 and 13 carried by the rotors7 and 7 The end transverse sections 1 and, 5 of the casing are cast intosuitable shape and formation to form the main casing su ports withbases1 and 5 resting' upon t e base 9 and secured theretoby the bolts 19, asindicated. The intermediate transverse sections 2, 3 and 4 llustrationof are held iirmly in position between the end sections 1 and 5 by meansof the axially disposed bolts 6, these bolts passing through the endsections 1 or 5 and engaging screwthreaded openings in the middlesection 3. The intermediate sections 2 and 4 are of ring-like form andhave openings therethrough registering with the openings. in.

sections 1 and 3 or 3 and 5 respectively lfor bolts 6. -In theparticular embodiment illus- -trated there are eight of these boltsv 6,four on each end. The rin sections 2 and 4 define the eccentric cham ers18 aud 18.v The -middle section 3 is of disc-like form and separates'thechambers 18 and 18 from one another Itis providedthrough its center withan opening for lthe reception of the shaft 8, carrying the cylindrical-rotors 7 and 7?. It is also provided on each side with a cylindricalrecess 20 to receive in a closely fitting manner the ends of the rotors7 and 7 fit into similar recesses 21 formedon the inner faces of thetransverse members land 5. The rotors 7 and 7 fit tightly against theupper inner surface of the rlngs 2 and* 4 The other. sides of4the-rotorsv7y and 7 forming theV eccentric chambers 18 and 18 and thechamber 18" is incommunication formed in the upper part of theintermedie ate ring 4, a registering recess or opening 23 formed in-the'middle ringmember 3, and a communicating registering chamber 1 6formed in the intermediate ring 2. It is observed that the communicatingchambers 22 and 16 lead tothe chambers'1'8 and 18 at points on oppositesides of the contact line of the rotors 7 and 7', with the rin s 2 and4. On the other side of the rotor 1 op osite the connection 22, theeccentric cylin rical chamber 18 is connected -with the ex haust line bthe pipe-15, leading to an-opening throng the intermediate ring 4.- andsimilarly in the ring 2 there is provided an opening 17 leading. fromthe lchamber 18- on the side of the rotor 7 opposite the locapump isimmersed.V For convenience in asvsembly the shaft 8 upon which therotors: 7

and 7 are mounted, is` divided betweenfthe rotors 7 and 7 into acoupling 24 so as to enable the two rotors, with the shaft, .to bereadilfy and quickly assembledwith their4 65 the reception andaccommodation of the' coupling ends 24 passing through the centeropening in the middle transverse member 3. The shaft 8 at one end is.rovided with a suitable bearin `25 in the rame member 1 and suitable"earings 26 -with packing glands vtherein are provided in the end framemember' for the accommodation of the shaft. Similarly a bearing 10 withsuitable glands therein is provided on one end of thehousing 9 for thepassage therethrough f the 4shaft 8, and a pulley 11 is carried by theoverhanging end of the shaft as a driving medium. Any driving means maybe utilized as for example an electric motor (not shown for conveniencein illustration). The piston blades 12 and 13 `are mounted forreciprocable movements radially through the rotors 7 and-7', suitableslots being provided therethrough for the reception of these pistonblades. There is a pair of these blades for each piston and thekblades'of 4each pair are urged or biased in an outward direction bymeans of -intermediate compression springs 14 disposed within the slots,with their ends resting in sockets formed in t-he blades, there beingpro-V vided three of these compression springs 14 in each rotor. Theshaft 8 also is provided vwith a slot 35 registering with thecorresponding chambers of the rotors to provide for the unhinderedreciprocation of the piston blades 12 and 13 therethrough. At 27 isindicated a valve for preventing. the leakage of oil down into the pumpchamber through the outlet 17.

The operation of the compound pump is readily apparent from thediagrammatic illustration of Fig. 9. The two rotors 7 and 7 areassembled with their respectivevblades 12 and" 13 assuming the relativepositions illustrated. The blades 13 one after the other trap the aircoming in through the exhaust pipe 15 and carry the entrapped air aroundcounter-clockwise into the opening 22 from whence it escapes-through theopenings 23 and 16 into the chamber 18. The air is here again entrappedby the blades 12 as they pass the opening 16 and is forced out throughthe opening 17 leadlng to the 0 11 chamber, the two rotors 7 and 7 withtheir respective piston blades 12 and 13 cooperating and functioningtogether and operating in series in the manner indicated to eectivelvexhaust the air from the exhaust line 15. uThe valve 27 indicates an oilcheck valve for preventing the leakage of o1l. and

air down into the chamber-18l when the pump is not working. This valveincludes a casing or valve seat 27 which is ltool steel T he oil levelmay be, something like that indicated by the broken line 32 in Fig. 9.

The pump may be readily disassembled by disconnecting the bolts 6. Forexample, the transversesections 1 and 2 maybe taken down by removing thefour bolts 6 on the left end of Fig. 2 andthe rotor 7 th-en removed bysimply moving it longitudinally of the shaft so as to uncouple thecoupling 24. Similarly the 'other end of the pump may be disassembled bydisengaging the bolts 6 on the. right.

1. A vacuum pump comprising live transverse casing sections constructedand arranged to form when assembled in abutting relation two cylindricalchambers for the accommodation of two cylindrical rotors,'each of saidcylindrical chambers extending into the central casing section and intoone of the end casing sections and each being contained in part withinan eccentric chamber of larger diameter but of shorter length, eacheccentric chamber being tangent-to its associated cylindrical chamberalong the same line parallel to the axis, rotors for said cylindricalchambers having reciprocable pistonblades radially disposed therein andarranged to traverse the eccentric chambers of larger diameter, each ofsaid `eccentric chambers being provided with anoutlet and an inletdisposed on opposite sides of the said axially arallel line along whichthe eccentric and) the associatedA cylindrical chambers are tangent'toeach other anda connection between the outlet of one of saideccentric-chambers and theinlet of the other of said eccentric chamberscomprising registering passages through, thefintermediate and centrallcasing sections arranged so as to cause the rotors to function inseries.

2. A compound rotary pump comprising a casing having two end portionsland a central portion, said central portion being provided with anopening therethrough, cylindrical chambers within said casing, rotorsfor said chambers and shafts coupled within said opening for saidrotors.'

In testimony whereof., I have signed my name to this specification.

'CHARLES EISLER,

